Horton

Re: Minimal logical decoding on standbys

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Robert Haas <robertmhaas@gmail.com>
Cc: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Ibrar Ahmed <ibrar.ahmad@gmail.com>, Amit Khandekar <amitdkhan.pg@gmail.com>, fabriziomello@gmail.com, tushar <tushar.ahuja@enterprisedb.com>, Rahila Syed <rahila.syed@2ndquadrant.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2022-12-20T17:56:02Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Reduce the log level in 035_standby_logical_decoding.pl.

  2. 035_standby_logical_decoding: Add missing waits for replication

  3. For cascading replication, wake physical and logical walsenders separately

  4. Handle logical slot conflicts on standby

  5. Support invalidating replication slots due to horizon and wal_level

  6. Prevent use of invalidated logical slot in CreateDecodingContext()

  7. Replace replication slot's invalidated_at LSN with an enum

  8. Pass down table relation into more index relation functions

  9. Assert only valid flag bits are passed to visibilitymap_set()

  10. Remove unused _bt_delitems_delete() argument.

  11. Add xl_btree_delete optimization.

On 2022-12-16 11:38:33 -0500, Robert Haas wrote:
> On Fri, Dec 16, 2022 at 10:08 AM Drouvot, Bertrand
> <bertranddrouvot.pg@gmail.com> wrote:
> > > After 1489b1ce728 the name mayConflictInLogicalDecoding seems odd. Seems
> > > it should be a riff on snapshotConflictHorizon?
> >
> > Gotcha, what about logicalSnapshotConflictThreat?
> 
> logicalConflictPossible? checkDecodingConflict?
> 
> I think we should try to keep this to three words if we can. There's
> not likely to be enough value in a fourth word to make up for the
> downside of being more verbose.

I don't understand what the "may*" or "*Possible" really are
about. snapshotConflictHorizon is a conflict with a certain xid - there
commonly won't be anything to conflict with. If there's a conflict in
the logical-decoding-on-standby case, we won't be able to apply it only
sometimes or such.

How about "affectsLogicalDecoding", "conflictsWithSlots" or
"isCatalogRel" or such?

Greetings,

Andres Freund